Corrugated fiberboard boxes or the like are widely utilized for the storage and shipping of a variety of materials. A frequently utilized design for the construction of such boxes involves an arrangement wherein: the box has four sides; and, four flaps are provided at opposite ends of the box, each set of four flaps comprising two pair of opposite flaps. Typically, during sealing the pairs of flaps are folded toward one another in such a manner that an elongate seam is provided across both the top and bottom portions of the box. In sealing such boxes, adhesive tape is generally extended longitudinally along a seam to be sealed. Typically, an extension of tape somewhat longer than the seam is used, and the tape extension is wrapped over end panels of the box, for securement. In general, such end extensions of tape are usually at least about 2-4 inches (5-11 cm) long, so that a secure adhesive engagement with a relatively significant side or end surface area of carton is obtained. In many situations such sealing arrangements of adhesive tape are applied to both the top and the bottom of a carton.
Automatic apparatus have been developed to accomplish application of sealing tape in the above manner to conventional, relatively deep, boxes or cartons of the type described. Typically, for such arrangements, the boxes are fed into the apparatus end-wise, so that a tape head or applicator applies the tape: first to a lead side (or end) of the box; then across either the top or bottom of the box to seal a seam by extension to the opposite side or end; and, finally, somewhat down the opposite (rear) side (or end). Some conventional arrangements provide for application of tape to both top and bottom surfaces of the carton being sealed.
Conventional arrangements have worked quite well, for application to relatively deep cartons. One such commercial arrangement is available from the Assignee of the present invention, Minnesota Mining and Manufacturing Corporation, St. Paul, Minn., under the tradename 3M-Matic.TM. 22A Adjustable Case Sealer.
Some carton designs, however, although frequently used are not susceptible to good secure sealing via the above methods, and with such conventional apparatus. One such style of carton is the "book-fold" carton. This type of carton is generally very shallow, usually about 0.25-3.0 inch (0.6-7.5 cm) deep, and includes only one seam for sealing. A representative conventional book-fold carton is depicted at reference numeral 1, FIG. 1.
As used herein the term "book-fold carton" shall be understood to refer to any carton which is closed by folding laterial flaps together, over a unitary back panel. Such a carton has an open seam on the top, but none on the bottom. The book-fold carton of FIG. 1 is a one-piece carton. Two- and three-piece book-fold cartons are also known, see for example "Fiber Box Handbook", Packaging Corporation of America, p. 44, incorporated herein by reference. Multi-piece arrangements may be sealed according to the principles of the present invention, discussed in detail below.
At reference numeral 2, FIG. 2, carton 1 as shown have been sealed by means of a conventional arrangement of tape 4. An important difference exists between: the manner and arrangement by which adhesive tape 4 is applied to book-fold carton 1; and, the way such tape is applied to conventional, relatively deep, cartons. First, as previously indicated, for the book-fold carton the only longitudinal seam which needs to be sealed is that on surface 5 of the box, i.e. the seam indicated in phantom at numeral 6. That is, there is no analogous seam on a bottom side of the box. Thus, only one extension of tape 4 is needed to accomplish the sealing. A second important difference between sealing of a shallow carton 1, and deep cartons, is that at end surfaces 10 and 11, insufficient depth of surface is provided for good securement of the adhesive tape 4. As a result, end tabs, flaps or tails 15 of tape 4 are usually folded underneath carton 1, and are smoothed out (or buffed) in attachment to a surface (typically bottom) of the carton 2 opposite to surface 5. This type of tape arrangement is generally designated in the carton industry as a "C-clip".
In the production of "C-clip" folds of tape, it is necessary to provide a method whereby tails 15 can be buffed against, i.e. smoothly applied against, the surface of the carton 1, to which they are shown adhered in FIG. 2. A variety of means have been developed to accomplish this. None has been completely satisfactory. Problems have generally concerned: speed of the buffing steps; effective obtaining of a smooth, flat, wrinkle-free profile for the tails 15; development of mechanized systems to accomplish C-clip application relatively rapidly and efficiently; and, similar matters.
What has been needed has been an apparatus to accomplish the "buffing" or "smoothing" step of application of tape tails, especially those of the C-clip, wherein the short tails, tabs or extensions of tape eventually located on an opposite side of the carton from the seam being sealed, are smoothed and pressed (or buffed) into position. What has particularly been needed has been an apparatus for effecting this, in accomplishment with otherwise conventional or modified conventional carton or case sealing arrangements. A method for accomplishing such buffing of tails of tape, preferably by means of such an apparatus, has also been needed.